qmk-firmware/tmk_core/common/chibios/printf.c

/*
 * found at: http://www.sparetimelabs.com/tinyprintf/tinyprintf.php
 * and:      http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
 */

/*
File: printf.c

Copyright (C) 2004  Kustaa Nyholm

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

#include "printf.h"

typedef void (*putcf)(void*, char);
static putcf stdout_putf;
static void* stdout_putp;

// this adds cca 400 bytes
#define PRINTF_LONG_SUPPORT

#ifdef PRINTF_LONG_SUPPORT

static void uli2a(unsigned long int num, unsigned int base, int uc, char* bf) {
    int          n = 0;
    unsigned int d = 1;
    while (num / d >= base) d *= base;
    while (d != 0) {
        int dgt = num / d;
        num %= d;
        d /= base;
        if (n || dgt > 0 || d == 0) {
            *bf++ = dgt + (dgt < 10 ? '0' : (uc ? 'A' : 'a') - 10);
            ++n;
        }
    }
    *bf = 0;
}

static void li2a(long num, char* bf) {
    if (num < 0) {
        num   = -num;
        *bf++ = '-';
    }
    uli2a(num, 10, 0, bf);
}

#endif

static void ui2a(unsigned int num, unsigned int base, int uc, char* bf) {
    int          n = 0;
    unsigned int d = 1;
    while (num / d >= base) d *= base;
    while (d != 0) {
        int dgt = num / d;
        num %= d;
        d /= base;
        if (n || dgt > 0 || d == 0) {
            *bf++ = dgt + (dgt < 10 ? '0' : (uc ? 'A' : 'a') - 10);
            ++n;
        }
    }
    *bf = 0;
}

static void i2a(int num, char* bf) {
    if (num < 0) {
        num   = -num;
        *bf++ = '-';
    }
    ui2a(num, 10, 0, bf);
}

static int a2d(char ch) {
    if (ch >= '0' && ch <= '9')
        return ch - '0';
    else if (ch >= 'a' && ch <= 'f')
        return ch - 'a' + 10;
    else if (ch >= 'A' && ch <= 'F')
        return ch - 'A' + 10;
    else
        return -1;
}

static char a2i(char ch, const char** src, int base, int* nump) {
    const char* p   = *src;
    int         num = 0;
    int         digit;
    while ((digit = a2d(ch)) >= 0) {
        if (digit > base) break;
        num = num * base + digit;
        ch  = *p++;
    }
    *src  = p;
    *nump = num;
    return ch;
}

static void putchw(void* putp, putcf putf, int n, char z, char* bf) {
    char  fc = z ? '0' : ' ';
    char  ch;
    char* p = bf;
    while (*p++ && n > 0) n--;
    while (n-- > 0) putf(putp, fc);
    while ((ch = *bf++)) putf(putp, ch);
}

void tfp_format(void* putp, putcf putf, const char* fmt, va_list va) {
    // This used to handle max of 12, but binary support jumps this to at least 32
    char bf[36];

    char ch;

    while ((ch = *(fmt++))) {
        if (ch != '%')
            putf(putp, ch);
        else {
            char lz = 0;
#ifdef PRINTF_LONG_SUPPORT
            char lng = 0;
#endif
            int w = 0;
            ch    = *(fmt++);
            if (ch == '0') {
                ch = *(fmt++);
                lz = 1;
            }
            if (ch >= '0' && ch <= '9') {
                ch = a2i(ch, &fmt, 10, &w);
            }
#ifdef PRINTF_LONG_SUPPORT
            if (ch == 'l') {
                ch  = *(fmt++);
                lng = 1;
            }
#endif
            switch (ch) {
                case 0:
                    goto abort;
                case 'u': {
#ifdef PRINTF_LONG_SUPPORT
                    if (lng)
                        uli2a(va_arg(va, unsigned long int), 10, 0, bf);
                    else
#endif
                        ui2a(va_arg(va, unsigned int), 10, 0, bf);
                    putchw(putp, putf, w, lz, bf);
                    break;
                }
                case 'd': {
#ifdef PRINTF_LONG_SUPPORT
                    if (lng)
                        li2a(va_arg(va, unsigned long int), bf);
                    else
#endif
                        i2a(va_arg(va, int), bf);
                    putchw(putp, putf, w, lz, bf);
                    break;
                }
                case 'x':
                case 'X':
#ifdef PRINTF_LONG_SUPPORT
                    if (lng)
                        uli2a(va_arg(va, unsigned long int), 16, (ch == 'X'), bf);
                    else
#endif
                        ui2a(va_arg(va, unsigned int), 16, (ch == 'X'), bf);
                    putchw(putp, putf, w, lz, bf);
                    break;
                case 'c':
                    putf(putp, (char)(va_arg(va, int)));
                    break;
                case 's':
                    putchw(putp, putf, w, 0, va_arg(va, char*));
                    break;
                case 'b':
#ifdef PRINTF_LONG_SUPPORT
                    if (lng)
                        uli2a(va_arg(va, unsigned long int), 2, 0, bf);
                    else
#endif
                        ui2a(va_arg(va, unsigned int), 2, 0, bf);
                    putchw(putp, putf, w, lz, bf);
                    break;
                case '%':
                    putf(putp, ch);
                default:
                    break;
            }
        }
    }
abort:;
}

void init_printf(void* putp, void (*putf)(void*, char)) {
    stdout_putf = putf;
    stdout_putp = putp;
}

int tfp_printf(const char* fmt, ...) {
    va_list va;
    va_start(va, fmt);
    tfp_format(stdout_putp, stdout_putf, fmt, va);
    va_end(va);

    return 1;
}

static void putcp(void* p, char c) { *(*((char**)p))++ = c; }

int tfp_sprintf(char* s, const char* fmt, ...) {
    va_list va;
    va_start(va, fmt);
    tfp_format(&s, putcp, fmt, va);
    putcp(&s, 0);
    va_end(va);

    return 1;
}